ItemArticle

Presence of red giant population in the foreground stellar substructure of the Small Magellanic Cloud

Title
Presence of red giant population in the foreground stellar substructure of the Small Magellanic Cloud
Creator
James D.; Subramanian S.; Omkumar A.O.; Mary A.; Bekki K.; Cioni M.-R.L.; De Grijs R.; El Youssoufi D.; Kartha S.S.; Niederhofer F.; Van Loon J.T.
Description
The eastern region of the Small Magellanic Cloud (SMC) is found to have a foreground stellar substructure, which is identified as a distance bimodality (?12 kpc apart) in the previous studies using red clump (RC) stars. Interestingly, studies of red giant branch (RGB) stars in the eastern SMC indicate a bimodal radial velocity (RV) distribution. In this study, we investigate the connection between these two bimodal distributions to better understand the nature and origin of the foreground stellar substructure in the eastern SMC. We use the Gaia Early Data Release 3 astrometric data and archival RV data of RGB stars for this study. We find a bimodal RV distribution of RGB stars (separated by ?35-45 km s-1) in the eastern and south-western (SW) outer regions. The observed proper motion values of the lower and higher RV RGB components in the eastern regions are similar to those of the foreground and main-body RC stars, respectively. This suggests that the two RGB populations in the eastern region are separated by a similar distance to those of the RC stars, and the RGB stars in the lower RV component are part of the foreground substructure. Based on the differences in the distance and RV of the two components, we estimate an approximate time of formation of this substructure as 307 65 Myr ago. This is comparable with the values predicted by simulations for the recent epoch of tidal interaction between the Magellanic Clouds. Comparison of the observed properties of RGB stars, in the outer SW region, with N-body simulations shows that the higher RV component in the SW region is at a farther distance than the main body, indicating the presence of a stellar counter-bridge in the SW region of the SMC. 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.
Source
Monthly Notices of the Royal Astronomical Society, Vol-508, No. 4, pp. 5854-5863.
Date
2021-01-01
Publisher
Oxford University Press
Subject
galaxies: individual: Small Magellanic Cloud; galaxies: interactions; Magellanic Clouds; proper motions; stars: kinematics and dynamics
Coverage
James D., Department of Physics, Christ (Deemed to Be) University, Bangalore, 560029, India; Subramanian S., Indian Institute of Astrophysics, Koramangala II Block, Bangalore, 560034, India; Omkumar A.O., Indian Institute of Astrophysics, Koramangala II Block, Bangalore, 560034, India, Leibniz-Institut fur Astrophysik Potsdam (AIP), An der Sternwarte 16, Potsdam, D-14482, Germany, Institut fur Physik und Astronomie, Universitat Potsdam Haus 28, Karl Liebknecht Str 24/25, Golm (Potsdam), D-14476, Germany; Mary A., Department of Physics, Christ (Deemed to Be) University, Bangalore, 560029, India; Bekki K., ICRAR M468, University of Western Australia, 35 Stirling Highway, Crawley, 6009, WA, Australia; Cioni M.-R.L., Leibniz-Institut fur Astrophysik Potsdam (AIP), An der Sternwarte 16, Potsdam, D-14482, Germany; De Grijs R., Leibniz-Institut fur Astrophysik Potsdam (AIP), An der Sternwarte 16, Potsdam, D-14482, Germany, Research Centre for Astronomy, Astrophysics and Astrophotonics, Macquarie University, Balaclava Road, Sydney, 2109, NSW, Australia; El Youssoufi D., Leibniz-Institut fur Astrophysik Potsdam (AIP), An der Sternwarte 16, Potsdam, D-14482, Germany, Institut fur Physik und Astronomie, Universitat Potsdam Haus 28, Karl Liebknecht Str 24/25, Golm (Potsdam), D-14476, Germany; Kartha S.S., Department of Physics, Christ (Deemed to Be) University, Bangalore, 560029, India; Niederhofer F., Leibniz-Institut fur Astrophysik Potsdam (AIP), An der Sternwarte 16, Potsdam, D-14482, Germany; Van Loon J.T., Lennard-Jones Laboratories, Keele University, Keele, ST5 5BG, United Kingdom
Rights
All Open Access; Green Open Access
Relation
ISSN: 358711; CODEN: MNRAA
Format
Online
Language
English
Type
Article

Collection

Articles

Citation

James D.; Subramanian S.; Omkumar A.O.; Mary A.; Bekki K.; Cioni M.-R.L.; De Grijs R.; El Youssoufi D.; Kartha S.S.; Niederhofer F.; Van Loon J.T., “Presence of red giant population in the foreground stellar substructure of the Small Magellanic Cloud,” CHRIST (Deemed To Be University) Institutional Repository, accessed February 25, 2025, https://archives.christuniversity.in/items/show/15571.

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